Design, synthesis, and biological evaluation of phenyloxadiazole derivatives as potential antifungal agents against phytopathogenic fungi

A novel series of picarbutrazox-inspired oxadiazole hybrids was synthesized and the derivatives’ biological activity against phytopathogenic fungi was investigated. The molecules were designed by retaining the active fragment of tetrazolyl phenyloxime ether of lead compound picarbutrazox, while introducing the potentially active oxadiazole-derived fragment. Bioassay results revealed that some of the title compounds showed potent in vivo antifungal activities to control cucumber downy mildew. Therefore, this novel oxadiazole phenyloxadiazole derivative can be used as a potential antifungal agent to control cucumber downy mildew and other phytopathogenic fungi for crop protection.